The invention relates to a vehicle heater with a heating unit comprising an air intake connection and an exhaust connection, which connections can be placed in communication with corresponding inlet and outlet ducts through the bottom of a vehicle.
Such vehicle heaters, which are also called auxiliary or parking heaters, are customarily mounted on the inside of the vehicle bottom and project, with their coupling pipes for exhaust and air intake, through bores in the vehicle bottom to the outside. The exhaust manifold and a fresh air supply conduit--possibly leading to a filter--are mounted to these coupling pipes, usually with the aid of a pipe clamp. The coupling clamps are exposed to dirt and splash water, since they are located at the bottom of the vehicle, so that they corrode to such an extent that they can no longer be disassembled, as a rule, in case the heater is to be dismounted for purposes of repairs or servicing.
Therefore, the present invention has a primary object of providing a vehicle heater, of the type discussed above, wherein the heating unit, even after several years of operation, can be rapidly and conveniently dismantled for servicing purposes.
A vehicle heater wherein the object has been attained, in accordance with a preferred embodiment, by the provision of a coupling unit which is mountable to the vehicle bottom and comprises plug couplings or contact pressure couplings that are equipped with gaskets for receiving the connections, and have, associated therewith, coupling pipe sections oriented toward the outside.
As a result of providing a coupling unit, the coupling pipe sections of which point to the outside and are there connected, with the aid of clamps or the like, to the exhaust manifold and/or to the air intake manifold, corrosion of the coupling clamps is not troublesome because the installed coupling unit remains likely mounted to the vehicle bottom, even in case the heating unit is removed, only the heating unit being taken out of the plug or contact pressure couplings. Since the heating unit is removed from the plug or contact pressure couplings merely by pulling its coupling pipes out, dismantling and assembly are extremely convenient and time-saving.
The fuel feed line for the vehicle heater may be extended through a bore through the vehicle bottom outside of the coupling unit and may be attached by means of a clamp in the interior of the vehicle at the fuel connection of the heating unit. According to an especially advantageous embodiment of the invention, however, the provision is made that the coupling unit, in its wall on the vehicle side and in its outside wall, has, respectively, one perforation for the fuel supply; that a fuel line can be attached to the fuel connection by means of a clamp located within the coupling unit; and that the fuel line has an excessive length sufficient for lifting the heating unit. This construction ensures that the coupling clamp for the fuel line is seated in a protected fashion in the interior of the coupling unit and consequently is not exposed to danger of corrosion. On account of the fact that the fuel line has a certain excessive length, the heating unit can be lifted out of its seat and then the fuel connecting clamp on the inside of the vehicle can be detached. Depending on the space available and on the type of vehicle, the vehicle heater can be mounted to the inside or to the outside of the vehicle bottom. With a view toward saving material, it is advantageous in both cases to have the coupling unit open on the side facing the vehicle bottom. In this case, the vehicle bottom represents the outside or inside wall of the coupling unit.
According to another advantageous embodiment of the invention, the heating unit can be pressed, with the aid of a clamping strap, against the coupling unit, whereby the connections are securely disposed in the plug or contact pressure coupling of the coupling unit.
Advantageously, the respective plug coupling consists of a ring gasket pressed in place between two parallel plates, each of which has a concentric, circular opening; the inside diameter of this ring gasket is somewhat smaller than the inside diameter of the openings; the plate located toward the outside of the vehicle carries the coupling pipe section, respectively leading to the vehicle, concentrically to its circular opening.
An especially satisfactory mounting of the coupling pipes can be obtained if, according to another advantageous embodiment, the respective plug coupling is constituted by a guiding pipe exhibiting on its inner wall at least one groove or crimp wherein an O-ring is arranged. An embodiment which is especially simple in structural respects and thus is preferred resides in that the respective plug coupling consists of a ring gasket having a continuous groove on the outside, the two lateral faces of this groove encompassing the rim of a hole in a carrier plate.
In order to be able to conveniently remove the heating unit from its mounting even while the fuel line is attached, the provision is made that the perforation in the wall of the coupling unit on the vehicle side has an inside diameter larger than the maximum radial dimension of the coupling clamp. To safely avoid penetration of fuel vapors into the interior of the vehicle in such a case, the provision is made that a disk with a gasket is mounted at the fuel supply connection of the heating unit, this disk covering the perforation in the wall on the vehicle side. This disk, together with the heating unit, is firmly pressed against the perforation and consequently establishes a perfect seal for the interior of the vehicle against gasoline or oil vapors.
Sealing of the vehicle interior against gasoline vapors or oil vapors can also be safely obtained by providing the fuel connection pipe with a sealing plug seated, with the interposition of a gasket, tightly within the perforation of the wall of the coupling unit on the vehicle side. Also in this case, the perforation can be made adequately large to be able to pull the coupling clamp into the interior of the vehicle when the heating unit is removed. Yet, the sealing plug ensures a tight seat of the fuel connection pipe on the wall of the coupling unit on the inside of the vehicle and thus seals the vehicle interior against fuel vapors.
To avoid penetration of splash water into the inner space of the coupling unit, another advantageous embodiment provides that the fuel line can be sealed with respect to the rim of the perforation in the outside wall of the coupling unit by means of an edge protector. It is suitable in this case to make the contact pressure of the edge protector lower than the contact pressure of the gasket in the perforation on the vehicle side, since in case of an escape of gasoline or oil vapors, the sealing effect of the edge protector would overcome, due to the excess pressure, earlier than the sealing effect of this gasket, and, accordingly, the exiting fuel vapor would be passing to the outside rather than into the interior of the vehicle.
It is advantageous from the viewpoint of safety to mount the coupling unit to the vehicle bottom with the interposition of a gasket which extends all around.
According to another advantageous embodiment, gasoline or oil vapors (should they be liberated in the interior of the coupling unit) and safely be exhausted to the outside by means of a ventilating opening permitting the entrance of air into the interior of the coupling unit, but preventing the entrance of splash water.
The installation and dismantling of the heating unit can, furthermore, be simplified by equipping the coupling unit with a quick-action coupling for the detachable, tight connection of a fuel line with a fuel connection pipe of the heating unit. The provision of several perforations in the vehicle bottom is avoided, if, in a further embodiment of the invention, the coupling pipe sections and optionally a fuel connection pipe are extended through a single cutout in the vehicle bottom, sealed by means of a gasket extending all around.
The coupling pipe sections can be fashioned in an especially advantageous manner as angled pipes that are rotatable with respect to the coupling unit about the axes of the exhaust connection and/or the air intake connection. Thus, the direction of the exhaust flow and the direction of the combustion air intake can be adjusted as desired in a simple way. There is no need for additional exhaust and combustion air intake elbows. The structural height can be kept small. In this arrangement, the structure becomes especially simple if the angled pipes have an annular flange projecting toward the outside and are rotatably supported above a contact surface of the coupling unit. A perfectly sealing plug connection can, in such a case, be attained with comparatively little expenditure by providing that the contact surface is the bottom of a gasket housing for accommodating the gasket of the plug coupling and is fashioned as an elastic sealing ring; and that the sealing ring arranged above the annular flange sealingly contacts, with its underside, the annular flange and, on the inside, the exhaust connection and the air intake connection, respectively.
In a further embodiment of the invention, the coupling unit can exhibit a dish-shaped cast base. The assembly of the coupling unit is thereby simplified. Suitably, a plate-shaped gasket having perforations for the air intake connection, the exhaust connection, and the fuel feed is disposed between the flange portion of the base and the vehicle bottom. Such a gasket reliably precludes the penetration of splash water into the interior of the vehicle. In case of a quick-action mounting base in the form of a cast component, the angled pipes underneath the vehicle bottom are advantageously connected rotatably with the free ends of cast collars of the base, which collars accommodate, with a clearance, the free ends of the exhaust connection and of the air intake connection. Preferably, the mutually facing ends of the angled pipes and of the cast collars are equipped with complementary rotary guides, and the mutually facing ends of the angled pipes and cast collars are also provided with outwardly projecting annular flanges held together by a V-clamp encompassing the annular flanges. Since, in this arrangement, the coupling sites of the angled pipes and of the cast collars lie outside of the vehicle, they need to gastight seal.
To provide a seal with respect to the interior of the vehicle, respectively, one sealing ring is placed, preferably, on the exhaust connection and on the air intake connection, this sealing ring being sealingly disposed between the outer wall of the heating unit and a contact surface on the topside of the base, the base having advantageously an annular duct on its topside arranged concentrically to the cast collar accommodating the exhaust connection, a sealing ring being arranged in the annular duct which sealingly engages the outer wall of the heating unit. This results in a further improvement of the seal in the critical zone of the exhaust connection.
The fuel connection pipe suitably carries a sealing plug in the direction toward the heating unit, this plug being encompassed by a sealing ring. To be able to separate the fuel line easily from the fuel connection pipe of the heating unit, even after a rather long period of operation, a further embodiment of the invention provides an advantageous design for the quick-action assembly base so that the latter, for the penetration of the fuel connection, has a cylindrical collar extending through a perforation of the vehicle bottom; and that a coupling pipe is detachably arranged at the fuel connection pipe, this coupling pipe, in turn, being attachable to the fuel line and carrying, between the mounting points with the fuel connection pipe and with the fuel line, a disk, which latter constitutes, together with the collar, a chamber vented toward the outside for receiving the connection between the fuel connection pipe and the coupling pipe.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.